The present invention is generally directed to a power system for providing power to a plurality of loads, such as, a computer system. The present invention is more particularly directed to such a power system which is capable of being sourced by redundant sources to provide flexibility and reliability.
There are many applications where a power system must provide reliable power to the system which it powers. A computer system is one example.
Previous computer systems were generally provided with their own AC input power supplies. These AC “front-end” supplies produced positive DC voltage outputs. From these positive DC voltage outputs, power subsystems produced mid-and low-rail voltages. When these computer systems needed to be adapted for use in the Telecom industry, power system redesign was required due to the −48 V DC voltages available to power the computer system. In the end, the computer system power supplies for the Telecom industry were difficult to design, required higher component density, were more expensive, and required long lead-times. To provide power supply redundancy for reliability, two similar supplies were generally employed.
The present invention addresses the above issues. For example, it provides a power system which may use −48 V DC directly to provide the necessary mid- and low-rail voltages. In accordance with a further feature, the present invention provides a power system which provides all of the voltages necessary for powering a Telecom industry computer system directly from the existing power environment negating the need for new “front-end” supply development. In accordance with a further feature provided by an embodiment of the present invention, redundant source inputs may be readily accommodated whether the source inputs are direct DC sources or DC sources derived from a separate AC supply. Also, such redundant sources may be mixed sources of AC “front-end” sources and DC sources. This permits the computer system to operate from both AC and DC feeds so that either feed can drop out and the computer will still be powered.